We propose to create a "Center for GEI Association Studies" in support of the NIH's Genes by Environment Initiative (GEI) at the Broad Institute, within the Genetic Analysis Platform. Our aim is to enable whole genome association scans to succeed by supplying high quality large-scale genotyping in an environment that has proven ability in industrial process, commitment to scientific rigor and a depth of analytic expertise. Specifically, according to the stated goals of the RFA, we will genotype at least 7200 samples in year one, and at least 12,000 in total over the first three years of the award. We will receive and qualify DNA samples from external investigators. Once qualified we will use the Affymetrix whole genome genotyping platform to carry out genotyping of 1M SNPs on a single array. We will also make available three other platforms for genotyping (Illumina Infinium, Illumina Golden Gate and Sequenom MassArray) as options for whole genome studies, or critically, to be used in rapid validation and follow up of putative associations. We will apply rigorous QC metrics and filters to supply "clean" data sets to users. Finally, we will work with the NCBI to deposit data according to the NIH's guidelines on data sharing in a timely and efficient manner. Given the fast pace of development of genetic analysis tools, we will continue to improve upon existing products in terms of content and quality and will drive forward the adoption of new technologies as they become available.